Multilayer films that include one or more layers of a polyurethane material are known. Some of these films are disclosed in U.S. Pat. Nos. 6,607,831, 5,405,675, 5,468,532 and 6,383,644 as well as International (PCT) Patent Application No. PCT/EP93/01294 (i.e., Publication No. WO 93/24551). Some of these films have been used in surface protection applications. For example, actual film products that have been used to protect the painted surface of selected automobile body parts include multilayer films manufactured by 3M Company, St. Paul, Minn., under the product designations Scotchcal™ high performance protective film PUL0612, PUL1212 and PUL1212DC. Each of these 3M Company film products includes a thermoplastic polyester polyurethane layer that is backed by a pressure sensitive adhesive (PSA) on one major surface and covered by a water-based polyester polyurethane layer on the opposite major surface.
The present invention is an improvement in such multilayer protective film technology.